Ok.. more info on the bug. Today (20190607 in both PDT and UTC) the url of https://api.weather.com/v2/pws/history/all?stationId=KCASARAT1&format=json&units=e&date=20190607&apiKey=<my-api-key>
returned data like 0: "stationID": "KCASARAT1",
"tz": "America/Los_Angeles",
"obsTimeUtc": "2019-06-07T07:04:55Z",
"obsTimeLocal": "2019-06-07 00:04:55",
"epoch": 1559891095,
...
last: "stationID": "KCASARAT1",
"tz": "America/Los_Angeles",
"obsTimeUtc": "2019-06-07T22:50:01Z",
"obsTimeLocal": "2019-06-07 15:50:01",
"epoch": 1559947801,
Same URL after 5pm PDT the rollover of UTC date to 20190608 returns 0: "stationID": "KCASARAT1",
"tz": "America/Los_Angeles",
"obsTimeUtc": "2019-06-06T07:04:54Z",
"obsTimeLocal": "2019-06-06 00:04:54",
"epoch": 1559804694,
...
last: "stationID": "KCASARAT1",
"tz": "America/Los_Angeles",
"obsTimeUtc": "2019-06-07T06:59:56Z",
"obsTimeLocal": "2019-06-06 23:59:56",
"epoch": 1559890796,
.. in other words, the COMPLETE data for 20190606 instead of the data for 20190607 after 5pm PDT.
Looks like a valid API bug to me...
Then trying with 20190608 (tomorrow for me) returns 0: "stationID": "KCASARAT1",
"tz": "America/Los_Angeles",
"obsTimeUtc": "2019-06-07T07:04:55Z",
"obsTimeLocal": "2019-06-07 00:04:55",
"epoch": 1559891095,
...
208: "stationID": "KCASARAT1",
"tz": "America/Los_Angeles",
"obsTimeUtc": "2019-06-08T00:24:54Z",
"obsTimeLocal": "2019-06-07 17:24:54",
"epoch": 1559953494,
which is the data I'd expect to continue seeing with a 20190607 query. Definitely an API bug.